Obstructive sleep apnea is more closely associated with bilateral primary aldosteronism than unilateral primary aldosteronism.

CONTEXT: Obstructive Sleep Apnea (OSA) has been implicated in the pathophysiology of primary aldosteronism (PA), yet its specific relationship with bilateral primary aldosteronism (BPA) remains unclear. Clarifying this association is essential for optimizing diagnostic and therapeutic strategies.

OBJECTIVE

To investigate the independent association between OSA and BPA, and compare clinical and sleep parameters between unilateral primary aldosteronism (UPA) and BPA.

METHODS

In this single-center cross-sectional cohort study, a total of 136 PA patients (79 UPA, 57 BPA) underwent comprehensive clinical, biochemical, and polysomnographic evaluations. Prevalence and severity of OSA were compared between groups. Logistic regression analyses, both crude and adjusted, assessed the independent association between OSA and BPA.

RESULTS

Compared to UPA, BPA patients exhibited significantly higher body weight, BMI, waist circumference, triglycerides, serum potassium, and baseline plasma renin concentration, but lower 24-hour urinary potassium, and plasma aldosterone concentrations (all P < 0.05). Patients with BPA demonstrated higher apnea-hypopnea index (AHI) [21.5(3,32.2) vs. 14.0(10.9,52.7), P = 0.008], higher obstructive apnea counts and lower the lowest oxygen saturation during sleep. Moderate-to-severe OSA prevalence was greater in BPA than UPA (61% vs. 48%; P = 0.004). Among patients with OSA, BPA prevalence significantly exceeded UPA (91% vs. 66%; P = 0.001). OSA patients also had higher BPA prevalence compared to non-OSA patients (50% vs. 16%; P = 0.001). Logistic regression revealed an independent association between OSA and BPA in both crude (OR 5.400, 95% CI 1.930-15.107; P = 0.001) and adjusted analyses (OR 9.91, 95% CI 1.19-82.67; P = 0.034).

CONCLUSION

OSA is significantly associated with increased BPA risk, exhibiting higher prevalence and severity in BPA patients compared to UPA. Our findings underscore the importance of routine OSA screening in PA patients, especially those with BPA, to improve outcomes and reduce cardiovascular risk.